Monolayer Support Control and Precise Colloidal Nanocrystals Demonstrate Metal–Support Interactions in Heterogeneous Catalysts
Monolayer Support Control and Precise Colloidal Nanocrystals Demonstrate Metal–Support Interactions in Heterogeneous Catalysts
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DOI：
10.1002/adma.202104533
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发表时间：
2021-09
影响因子：
29.4
通讯作者：
E. Goodman;Arun S. Asundi;A. Hoffman;K. Bustillo;J. Stebbins;S. Bare;S. Bent;M. Cargnello
中科院分区：
文献类型：
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作者：
E. Goodman;Arun S. Asundi;A. Hoffman;K. Bustillo;J. Stebbins;S. Bare;S. Bent;M. Cargnello
活性相和支撑相之间的电子和几何相互作用是决定非均相催化剂活性的关键，但金属-支撑相互作用的研究具有挑战性。本文展示了利用原子层沉积（ALD）和胶体纳米晶体合成方法的单层控制形成如何结合导致催化剂具有亚纳米精度的活性相和支撑相，从而允许详细研究金属-支撑相互作用。使用这种方法在发展的支持效应在钯催化甲烷燃烧的基本理解被证明。均匀的Pd纳米晶体沉积在Al2O3/SiO2球形支架上，通过控制形貌和Al2O3层厚度从亚单层到≈4 nm厚的均匀涂层制备。根据Pd/Al2O3界面上Al2O3的覆盖范围和结构的不同，催化活性发生了巨大的变化，即使是单层氧化铝也会使反应速率提高一个数量级。通过一层一层地构建Pd/Al2O3界面，并使用均匀的Pd纳米晶体，这项工作证明了受控和可调材料在确定金属-载体相互作用和催化剂活性方面的重要性。
Electronic and geometric interactions between active and support phases are critical in determining the activity of heterogeneous catalysts, but metal–support interactions are challenging to study. Here, it is demonstrated how the combination of the monolayer‐controlled formation using atomic layer deposition (ALD) and colloidal nanocrystal synthesis methods leads to catalysts with sub‐nanometer precision of active and support phases, thus allowing for the study of the metal–support interactions in detail. The use of this approach in developing a fundamental understanding of support effects in Pd‐catalyzed methane combustion is demonstrated. Uniform Pd nanocrystals are deposited onto Al2O3/SiO2 spherical supports prepared with control over morphology and Al2O3 layer thicknesses ranging from sub‐monolayer to a ≈4 nm thick uniform coating. Dramatic changes in catalytic activity depending on the coverage and structure of Al2O3 situated at the Pd/Al2O3 interface are observed, with even a single monolayer of alumina contributing an order of magnitude increase in reaction rate. By building the Pd/Al2O3 interface up layer‐by‐layer and using uniform Pd nanocrystals, this work demonstrates the importance of controlled and tunable materials in determining metal–support interactions and catalyst activity.